To find the minimum number of gloves Mr. Brown will have to pick to be certain to find a pair of gloves of the same color, we can use the Pigeonhole Principle.
The Pigeonhole Principle states that if you have more pigeons than pigeonholes, then at least one pigeonhole must contain more than one pigeon.
In this case, the "pigeons" are the gloves and the "pigeonholes" are the two colors (black and brown). Mr. Brown has 8 black gloves and 6 brown gloves, so the total number of gloves is 8 + 6 = 14.
To guarantee a pair of gloves of the same color, Mr. Brown must pick one more glove than the total number of colors available. Since there are 2 colors (black and brown), he must pick 2 + 1 = 3 gloves.
Therefore, the correct answer is D) 3.